Differential actuator



Dec. 19, 1950 A. G. RUSSELL DIFFERENTIAL ACTUATOR 3 Sheets-Sheet 1 Filed June 5, 1947 INV NTOR Wm a wsd/ BY 91m; flaw ATTORNEY Dec. 19, 1950 A. G. RUSSELL 2,534,376

DIFFERENTIAL ACTUATOR Filed June 5, 1947 3 Sheets-Sheet 2 Wm g; 5223/ ATTORN EY Patented Dec. 19, 1950 DIFFERENTIAL ACTUATOR Alva G. Russell, Stamford, Conn., assignor to Pitney-Bowes, Inc., Stamford, Conn., 21. corporation of Delaware Application June 5, 1947, Serial No. 752,738

8 Claims.

This invention relates to a calculating device, and more particularly to a settable differential actuator mechanism for use in entering a selected numeral value in an accumulator during a machine cycle of operation.

One type of actuator in common use provides for the drive of a toothed accumulator wheel by means of a selected one of several gear segments having teeth agreeing with a selected value which is to be registered. In another type of actuator .mechanism in common use, the accumulator .wheel or a part of drive mechanism geared thereto is removed from an operative relation with the .actuator after the selected value has been entered therein. With either of said actuators and other similar types of actuators, the accumulator wheel must be choked before and after the actuator functions to thereby prevent overthrow. Further, the drive of the accumulator is efiected in a relatively short part of an operating cycle. This increases the speed of rotation of the accumulator wheels unduly.

With the actuator of the present invention, a

constant meshed relation is maintained between the elements of the actuator and the toothed wheel of the accumulator. Hence, choke mechanism is not required. Further, a substantially a selected value in an accumulator during a machine cycle of operation, wherein an operative driving relation between the actuator and accumulator is constantly maintained.

It is another object to provide means for effecting a drive of a rotative actuator member having a fixed number of teeth, a distance equal to the difference between the number of teeth of said rotative actuator member and that of a settable variable toothed non-rotative actuator member.

It is another object to provide two concentric circular toothed rack members of different diameters one within the other, one being non-rotative and the other being rotative, and each having the same number of teeth when in a concentric relation, and including a cyclically driven pinion meshing with each rack, the said non-rotative rack being adjustable to vary the number of teeth and thereby eifect a differential drive of the rotative rack in accordance with a difference of the numbers of teeth thereof.

With the above and other objects in View, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it bein understood that various changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A preferred embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a front elevational view of the actuator mechanism with part broken away to show an accumulator member and showing the elements of the actuator in a 0 position;

Fig. 2 is a view similar to Fig. 1, but showing the actuator mechanism adjusted to the 9 value setting position;

Fig. 3 is a plan view; and

Fig. 4 is a vertical sectional view taken with the setting lever in a vertical position, and including the driving pinion element in its lower vertical position.

Referring to the drawings in detail, the actuator mechanism comprises a rotative circular rack member Ill having an inwardly extending sleeve portion H mounted within a bearing 12, which bearing is provided within a frame structure l3. The rotative rack I0 is cup shaped and ha rack teeth l4 around the circular edge thereof.

A second circular rack 15 is mounted around but in spaced relation to the rotative circular rack Ill. The circular rack I5 is constructed from a band which is looped into a circular form with the ends thereof overlapping, as clearly indicated in Fig. l, and is provided with rack teeth 16. The outer overlapping portion is secured to a bracket ll, which bracket is fixed to the frame l3. The inner end of the band has an opening i8 therein within which the upper arm of a setting lever I9 is tightly engaged. Said settin lever is mounted so as to rotate about the outside of the bearing l2, as best shown in Fig. 4.

A spacer ring is provided between the two circular racks l0 and 15 as indicated at 20 and is supported on a portion l3a projecting from one side of the frame 13. slots 20:; and 20b in said 3 ring provide clearance for the upper and lower arms of the setting lever l9 respectively. A slot |8a is also provided in the lower portion of the circular rack l5 to clear the lower arm of the setting lever IQ.

When the settin lever I9 is in the position, as in Fig. 1, the circular rack band IE will have been contracted to its minimum diameter and will be concentric with the rotative circular rack ill. Also, each of said circular racks lo and Hi, When in the latter 0 position will have the same number of rack teeth but with differing pitch, inasmuch as their diameters diiler.

When the setting lever i9 is adjusted to the value 9 position, as in Fig. 2, the circular rack IE will have become expanded and will have increased its number of teeth by nine.

A pinion 2| is rotatively mounted upon a shaft 22, which shaft is radially positioned relative to the teeth of the circular racks and is fixedly mounted in an enlarged end of, and at right angles to an actuator drive shaft 25!, as indicated at'23a. Said actuator drive shaft 23 extends through the sleeve portion ii of the rotative circular rack Hi, the same projecting outwardly therefrom as indicated in Fig. i. The pinion 2| is provided with a toothed portion 2 3 having the same pitch as the teeth of the non-rotative circular rack i5, also a shorter toothed portion 25 which has a pitch agreeing with the tooth pitch of the rotative circular rack iii. With the pinion 2| radially disposed relative to the rack teeth i l and It, the pinion teeth 2.5 and 241 will mesh therewith.

When the shaft 23 is rotated, which may be effected by any suitable hand operated means as indicated, or motive power means, the toothed portions 2:? and 25 of the pinion 2| will be rotated' around the teeth of the circular racks l0 and I5. Rotation of the pinion 2| will begin and end at the position indicated as the Home Position. When, after adjustment, there are more teeth in the non-rotative circular rack l5 than in the circular rack iii, rotation of the circular rack IE] will begin and end where the bulge of the circular rack t5 begins and ends, namely, beginning. at the Home Position and ending at. location. designated by the reference character A. The remaining toothed portion of the circular rack I5 is concentric with rotative circular rack I0 and no motion of the rotative circular rack occurs when the pinion moves over this concentric portion.

The circular rack I5, being non-rotative, will control the rotative circular rack ill and will ehect movement of said circular rack iii a distance equal to any difference in the number of teeth between each of said circular racks. For example,,.when the rack I5 is in the 0 or concentric position shown in Fig. 1, wherein as previously stated the teeth are equal in number in each rack, the pinion 2| will rotate about the teeth of each rack during a cycle of operation, without effecting rotation of the rotative circular rack Iii. When however, the circular rack I5 is adjusted to the 9 position, shown in Fig. 2 the pinion in following the contour of the toothed portion of the rack i5, will, during a cycle of operation, be driven by nine additional, teeth, which will cause the rotative cir- 4 cular rack ID will be driven a number of teeth equal to the value set.

A slot 26, provided in the bracket l1, provides clearance ior the setting lever lit to pass through during the setting operation. A clearance slot ii is also provided in the outer overlapping portion or the circular rack l5.

Accumulator mechanism is provided as indicated at as and, for the purpose of illustration, comprises a numeral wheel 2:: having a toothed portion ti, and is rotatively mounted upon a shalt 32. A gear Iixed to the inwardly extended portion of the sleeve II, has teeth 34 which mesh with the toothed portion 3| of the accumulator wheel 29.

when tnereioraa cycle of operation is effected during the rotation of the shaft 23 through 360, and a value has'been set to thereby increase the number of teeth in the circular rack I5 in accordance with the value set, the motion of w c n a u d h te o th circular racks will eiiect a drive of the l'otative circular a k w. a di ance a eei g with e s id se value. Said rotation or the circular rack H} will also ei'i'ect rotation of the gear 33, pin-ion 3t and the numeral wheel 2.9 accordingly. The numeral wheel 29 will therefore be rotated a distance agreeing with the set value and thus place the accumulated digit value in .a reading portionopposlte a window Through suitable transfer mechanism, such as indicated at 37, the tens values are transferred to a: numeral. wheel of higher order- Detent means may be provided as shownin Figs. 1 and 2,. by including a toothed segment portion at the lower end of the setting lever t9, and providing a spring urged pawl 36 to cooperate tl ierewith.

Several advantages obtained with the above described device include, the continuous engagement of the driving means (pinion 21) with the actuator control means, (circular racks l0; and Iii); changing the number of actuator teeth by the novelmethod oi increasing the rack circumference of one oi the circular racks; providing a dilierential drive through one rotative and one non-rotahve circular rack; and producing what is essenti'aally a slow motion drive of the accumulator, that is, taking a; substantially full cycle to eii'ect actuation ofany one of the nine dig-it values in the accumulator;

Having described the invention, what is claimed is:

1. In a calculating device, the combination of accumulating mechanism including a toothed Wheel, differential actuating means therefor comprising a circular roltative toothed member having teeth around the entire, circular edgeportion thereof and geared to the toothed wheel, a circular nonrotative tootl'ledv member. having teeth around the, entire. circular edge portion thereof, one oi said toothed; members including mea s to? var the numb i t eth er ei, P i ea w lr e in wi h h ee h o com t ai a d. ono a es es bed m ag and yn c d iv o enac in sweeten v e t a rini nar n heee Qt th combined toothed members to thereby eflject rotation of the rotative toothed member and toothed wheellof the accumulating mechanism in accordance with any difference in the numbers of teeth of the twotoothed. members.

2. In a calculating device, thecombination, accumulating mechanism. including a toothed wheel, differential actuating means therefor comprising a rotative toothed circular rack member having teeth around the entire circular rack edge thereof and geared to the toothed wheel, a non-rotative toothed circular rack member having teeth around the entire circular rack edge thereof, one of said rack members including means to vary the number of teeth thereof, a pinion continuously meshing with the teeth of both the rotative and non-rotative rack members, and a cyclical drive for effecting planetary movement of said pinion around the teeth of the combined rack members to thereby effect rotation of the rotative rack member and toothed wheel of the accumulating mechanism in accordance with any difference in the numbers of teeth of the toothed rack members.

3. In a calculating device, the combination of accumulating mechanism including a toothed wheel, differential actuating means therefor comprising a circular and rotative toothed rack member having teeth around the entire circular rack edge thereof geared to the toothed wheel, a circular and non-rotative toothed rack member having teeth around the entire circular rack edge thereof and encircling the rotative rack member, said latter rack member including means to vary the number of teeth thereof, a pinion radially positioned relative to and continuously meshing with the teeth of the rack members, and a cyclical drive for effecting planetar movement of said pinion around the teeth of the two rack members to thereby effect rotation of the rotative rack member and toothed wheel of the accumulating mechanism in accordance with any difference in the numbers of teeth of the toothed rack members.

4. A differential actuator comprising a circular and non-rotative toothed member having teeth around the entire circular edge portion thereof, settable means connected with the nonrotative toothed member and adapted to arrange a predetermined number of teeth in an actuating position, a circular and rotative toothed member having a fixed number of teeth around the entire circular edge portion thereof, a pinion continuously meshing with both the non-rotative and rotative toothed members, and means to effect plantary movement of the pinion around the teeth of the combined toothed members, whereby any variation between the teeth of the said toothed members will effect rotation of the rotative toothed member accordingly.

5. A differential actuator comprising a nonrotative circular toothed rack having teeth around the entire circular rack edge portion thereof, a rotative circular toothed rack within the non-rotative rack and having teeth around the entire circular rack edge portion thereof, said non-rotative rack being adjustable to vary the number of teeth within a predetermined limit, a pinion radially disposed relative to the circular racks and continuously meshing with the teeth of each rack, and a cyclically operable drive to effect planetary movement of the pinion around the teeth of said racks and thereby effect a drive of the rotative rack when the teeth of the non-rotative rack are greater in number than teeth of the rotative rack.

6. A differential actuator comprising a nonrotative circular toothed rack having teeth around the entire circular rack edge portion thereof, a rotative circular toothed rack arranged within the non-rotative rack and having teeth around the entire circular rack edge portion thereof, said non-rotative rack having the same number of teeth as the rotative rack under one condition and being adjustable to include additional teeth within a predetermined limit, a pinion radially disposed relative to the circular racks and continuously meshing with the rack teeth of each rack, and a cyclically operable drive to effect planetary movement of the pinion around the teeth of said racks and thereby effect a drive of the rotative rack when the teeth of the non-rotative rack are greater in number than the teeth of the rotative rack.

7. A differential actuator comprising a spirally wound toothed rack band arranged in a non-rotative position, a rotative circular toothed rack arranged within the spirally wound rack, said spirally wound rack being adjustable to increase or decrease its circumference and thereby vary the number of teeth within a predetermined limit, a pinion radially disposed relative to the said racks and continuously meshing with the teeth of each rack, and a cyclically operable drive to effect planetary motion of the pinion around the teeth of said racks and thereby effect a drive of the rotative rack when the teeth of the non-rotative rack are greater in number than teeth of the rotative rack.

8. A differential actuator comprising a spirally Wound toothed rack band arranged in a non-rotative position, a rotative circular toothed rack arranged within the spirally wound rack, said spirally wound rack having the same number of teeth as the rotative rack when in a 0 position and being adjustable to increase the circumference thereof and thereby provide additional teeth, a pinion radiall disposed relative to the said racks and continuously meshing with the teeth of each rack, and a cyclically operable drive to effect planetar motion of the pinion around the teeth of said racks and thereby effect a drive of the rotative rack the equivalent of one tooth for each tooth increase of the spirally wound toothed rack.

ALVA G. RUSSELL.

REFERENCES CITED ihe following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 773,632 Ensign Nov. 1, 1904 1,862,901 Martin June 14, 1932 2,137,524 Bugg Nov. 22, 1938 2,248,257 Thatcher July 8, 1941 2,313,183 Trbojevich Mar. 9, 1943 2,323,373 Bugg July 6, 1943 FOREIGN PATENTS Number Country Date 464,422 Great Britain Apr. 19, 1937 

